Method for separating the pulp from the skin of tomatoes

ABSTRACT

Methods are described for separating the pulp from the skin of fruit, such as tomatoes, in which each fruit is gripped and transported by mechanism along a continuously circular path, a cut to the skin of the fruit is produced by cutting device adjacent the path and the pulp is urged away from the gripping and transporting apparatus at a pulp discharge position while the skin remains gripped by that apparatus to separate the pulp from the skin.

This application is a division of application Ser. No. 253,373 filed4/13/81 now U.S. Pat. No. 4,355,572.

BACKGROUND OF THE INVENTION

This invention relates generally to the field of methods and apparatusfor peeling fruit. More particularly, it relates to methods andapparatus for peeling fruits, such as tomatoes, without the use ofcaustic chemicals.

The most common method and apparatus used in peeling fruits, such astomatoes, provide for scalding the fruit and then application of causticchemicals to remove the skin therefrom. Certain other types of apparatushave attempted various mechanical techniques for gripping the fruit andstripping the skin or peel therefrom. However, these prior methods andtypes of apparatus have suffered from numerous disadvantages. Thechemical type of peeling has necessitated the subsequent washing of thepeeled pulp to remove remaining traces of chemicals, a process which maydamage the pulp or remove otherwise edible portions thereof.Additionally, the juice resulting from the operation of these chemicaltype peeling devices has been unusable because of its contamination withthe chemicals.

The previously known mechanical peelers for fruit of this typefrequently have caused excessive damage and loss of usable pulp due tothe mechanical gripping arrangement, and have also suffered frommechanical breakdown because of the complex and sometimes delicatemoving parts necessary for satisfactory operation. Many types of thepreviously known mechanical peelers have also been suited only forpeeling tomatoes of a predetermined size, a characteristic whichrequires an additional preliminary step of sorting by size and theprovision of different machines for different sized fruit.

SUMMARY OF THE INVENTION

To overcome the disadvantages of the prior art, it is an object of thepresent invention to provide a method and apparatus for separating thepulp from the skin of fruit, such as tomatoes, which operate in asubstantially continuous manner without the use of chemical elements ormechanical elements which may damage the pulp. It is a further object ofthis invention to provide such method and apparatus which is capable ofhandling, without adjustment, fruit of different sizes and shapes, andwhich permit the recovery for subsequent packing of juice producedduring the peeling of the fruit.

To achieve the foregoing, as well as other objects, method and apparatusare provided for separating the pulp from the skin of fruit, such astomatoes, which are supplied to the apparatus. This method and apparatusprovides for gripping and transporting each of the supplied fruit alonga path between a receiving position and a pulp discharge position, withthe mechanism for gripping and transporting comprising two members forgrippingly contacting the outer surface of the fruit skin on oppositesides of a plane extending through the fruit. A cut is produced, by asuitable mechanism, through a portion of the fruit skin remote from thegripping and transporting mechanism and in a plane extending generallythrough the fruit, and then the pulp is urged away from the gripping andtransporting mechanism through the cut in the skin by additionalapparatus while the skin is retained and gripped, whereby the pulp maybe separated from the skin.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be described with reference to the accompanyingdrawings in which:

FIG. 1 is a partial front perspective view of a preferred embodiment ofthe apparatus of this invention and of one form of apparatus suitablefor practicing the method of this invention;

FIG. 2 is a fragmentary sectional view taken along line 2--2 of FIG. 1,illustrating the skin cutting method and apparatus;

FIG. 3 is a fragmentary sectional view taken along line 3--3 of FIG. 1;

FIG. 4 is a fragmentary sectonal view taken along line 4--4 of FIG. 1illustrating the separation of the fruit pulp from the skin; and

FIG. 5 is a side elevational view of an alternative embodiment of thegripping and transporting mechanism for the apparatus of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT

A particularly preferred embodiment for practicing the teachings of thisinvention is illustrated in the drawings of FIGS. 1 through 4.

As illustrated in FIG. 1, the apparatus of this invention comprises, ingeneral, a support frame 2, only part of which is illustrated, a drivemotor 4 and gear box 6 amounted to the support frame and connected by asuitable coupling, a vibratory feed trough 8 for feeding fruit to theapparatus, gripping and transporting means, such as wheel 10, and pulpdelivery chute 12, all of which are mounted to the frame 2. It may benoted that only a portion of the frame 2 is illustrated, since the frameis of relatively conventional construction, with the parts omitted beingconventional in nature.

Wheel 10, which serves as the gripping and transporting means in thisembodiment, may suitably comprise a pair of discs 14 and 14' (not shown)fabricated of a suitable metal, fastened together by conventionalfasteners and rigidly mounted to shaft 16. The ends of this shaft 16 arecarried by appropriate bearings, such as pillow blocks 18, mounted tothe frame 2. Adjacent to one end of shaft 16 is a fixed sprocket 20which is drivingly connected to gearbox sprocket 22 and an additionalsprocket 24 by means of an appropriate belt or chain drive.

Sprocket 24 is affixed to one end of shaft 26, which is attached toframe 2 by suitable bearings 28. Carried on and affixed to this shaft 26is rotating brush 30, which is used for purposes to be described below.Bearing blocks 28 may suitably be mounted for adjustable positioning inthe vertical direction to increase or decrease the force of engagementbetween the brush 30 and the periphery of wheel 10.

Also attached to frame 2 in a conventional manner, not shown, arearcuate supports 32 and 34, respectively. These supports are of anarcuate configuration having its radius of curvature centered at thecenter of shaft 16. Only fragments of these arcuate supports 32 and 34are illustrated, to avoid cluttering the drawing, since the method ofattachment of the support frame 2 is conventional.

Arcuate support 32, and corresponding support 32' (not shown but mountedon the opposite side of wheel 10) have adjustably mounted theretocross-bar support arm 36. This adjustable mounting, suitably by means bybrackets 38, permits positioning of the cross-bar 36 at different pointsalong the curvature of the support 32, for purposes to be describedbelow. Attached to this cross-bar 36 are both the pulp discharge chute12 and also a pair of arms 40 and 40', at the outer ends of which arerotatably attached pinch or compressor rollers 42 and 42', which aresuitably of a frusto-conical configuration. Suitable conventionalmounting apparatus may be provided, if desired, to permit adjustment ofthe spacing between the centers of the two rollers 42 and 42'.

Arcuate support 34, also carried by frame 2, and its non-illustratedcompanion 34' at the opposite end of frame 2, support the assemblyillustrated in the upper right-hand portion of FIG. 1. This assemblyincludes feed trough 8 and the cutting blade assembly 44. Thesecomponents are carried by cross-member 46 which is adjustably mounted toarcuate support member 34 by conventional means, such as a slot in theend of cross-bar 46 and a bridge member 48 over that slot and thesupport member 34, with similar structure at the opposite end. Thisarrangement provides for selectively repositioning the cross-bar 46 andits associated apparatus at various points along the arcuate support 34,for purposes to be described below.

Affixed to cross-bar 46 are bearing blocks 50 and 50', rotatablycarrying shaft 52. Rigidly affixed to shaft 52 are eccentric 54 andpulley or sprocket 56. Rotatably carried on shaft 52 is sleeve 58 towhich is affixed cutter arm 60. Rotatably attached, by means of asuitable bearing arrangement, to the end of arm 60 opposite sleeve 58 isa rotary cutting blade assembly 44, also illustrated in sectional viewof FIG. 2. This rotary cutting blade assembly 44 suitably comprises asharp, thin, disc-like blade 62 with a cutting-depth-limiting guide 64concentric with and positioned adjacent to one side of blade, 62,preferably with a second similar guide 64' positioned adjacent to theopposite side of blade 62. Attached to, or suitably made integral with,guide 64 is a pulley 66 which is drivingly engaged by drive belt 68,which also engages pulley 56 on shaft 52. The blade 62 guides 64 and 64'and pulley 66 may all be carried by arm 60, as illustrated in thesectional view of FIG. 2.

The trough 8 may be rigidly affixed by bracket 70 to resilientsupporting arms 72. The action of eccentric 54 affixed to shaft 52 andbearing against the underside of trough 8 serves to give a vibratory oroscillatory movement generally in a vertical direction to the trough 8upon rotation of the shaft 52. Shaft 52 is rotatably driven by sprocket74 affixed to the end thereof and which is drivingly engaged by the beltor chain 76, which is driven by sprocket 78 affixed to the output shaftof gearbox 6.

The general configuration of the gripping and transporting means of thewheel 10 may be seen more clearly in the sectional views of FIGS. 2through 4. As shown in these figures, as well as FIG. 1, the wheelassembly 10 comprises the metal support discs 14 and 14' carried by theshaft 16 and having at their periphery resiliently deflectable grippingmembers 80 and 80'. While the members 80 and 80' may suitably be formedof a single extruded member of a suitable synthetic resin, within thescope of this invention, it is preferred that they be formed of twoseparate flange members clamped between the discs 14 and 14', asillustrated in FIGS. 2 through 5. Suitably, the flange members 80 and80' may have concentric ridges which are received into correspondingconcentric grooves on the mutually facing surfaces of the disc 14 and14' to secure the resiliently deflectable members 80 and 80' againstradially outward movement, with respect to the discs 14 and 14'. It ispreferred that these deflectable members 80 and 80' be formed in themanner of endless annular members of a suitable synthetic resin andhaving an undeflected configuration substantially similar to thatillustrated in FIGS. 2 and 3. In this configuration, with the members 80and 80' extending toward one another in the direction toward thesupporting disc 14 and 14' the flanges defined by the deflectablemembers have a generally V-shaped cross-section extending radiallyoutwardly at the periphery of the discs 14 and 14', thus forming atrough-like structure around the periphery of the discs 14 and 14'.

As illustrated in FIG. 4, the resilient members 80 and 80' aredeflectable toward another to effect a squeezing force upon anythingwithin the trough portion. This squeezing is effected by the engagementof the axially outer surfaces of the members 80 and 80' by thefrusto-conical pinch rollers 42 and 42'. As noted above, these pinchrollers 42 and 42' are carried upon members 40 and 40' and are attachedthereto by suitable shaft 82 and 82' for rotation about the axisthereof. The rollers 42 and 42' are mounted and tapered in such a mannerthat the apex of the truncated conical configuration would be at thecenter of the main shaft 16 supporting the wheel 10, so that there willbe rolling surface contact between the engaged surfaces of the rollers42 and 42' and the axially outer surfaces of the resilient members 80and 80'.

FIG. 5 illustrates an alternative apparatus for gripping andtransporting in which the discs 14 and 14' are replaced by a pair ofspaced apart pulleys 84 and 82 and in which the deflectable members 80and 80', suitably in the form of a single V-shaped member, are stretchedaround those pulleys as an endless belt. With such a structure the feedtrough 8 can suitably deposit the fruit onto the belt adjacent to thetop of pulley 84 with the pinch rollers 42 being positioned adjacent topulley 82. The pulleys 82 and 84 would suitably be driven in a mannersimilar to the way the shaft 16 drives the discs 14 and 14' in theembodiment of FIG. 1.

From the foregoing description of the apparatus, the method of operationand of separating the pulp of a fruit from its skin may be seen to be asfollows.

Fruit to be peeled, such as tomatoes which have been scalded to loosenthe skin thereof, are transported along a conveyor system, which formsno part of this invention. At appropriate exit stations from theconveyor, the fruit are directed into the supply trough 8 of the presentapparatus, for delivery to the skin removing apparatus. This trough 8has imparted to it a vibratory motion, by means of eccentric 54 affixedto rotating shaft 52. The vibratory motion imparted to the trough 8 isprovided, in a manner well known in the art, to urge the fruit todescend the angled trough such that the stem axis, which extends throughthe stem and blossom ends of the fruit, remains generally aligned withthe longitudinal direction of the feed trough 8. This alignment of thestem axis is beneficial for peeling certain fruit such as Italiantomatoes, but is generally unnecessary for other types. It may be notedthat the angle of downward slope of feed trough 8 may be adjusted bymoving the cross-bar support member 46 to different positions on itsarcuate support 34. This may be accomplished by loosening the bridgemembers 48, repositioning the cross-bar 46, and retightenting the bridgemember 48. By adjusting this angle the rate of feed of the fruit and itspoint of reception into the gripping and transporting apparatus can beadjusted.

As illustrated in FIG. 1, the tomatoes 86 are delivered to the grippingand transporting apparatus (wheel assembly 10 in this preferredembodiment) at a point somewhat ahead of the uppermost portion of thewheel 10 in its rotary travel. As described above, while assembly 10carries the gripping and transporting means, which suitably comprisestwo resiliently deflectable members 80 and 80' for grippingly contactingthe outer surface of the skin of the fruit. The fruit contactingportions of the members 80 and 80', which in this embodiment areendless, annular members clamped together to form a trough-likestructure normally having a generally V-shaped cross-section, areprovided with ridges, dimples, grooves, or other surface characteristicssuitable for providing a firm gripping engagement with the outer skin ofthe fruit delivered thereto. Since the normal configuration of thesemembers 80 and 80', which form the radially outermost portions of thetransporting and gripping mechanism, is normally V-shaped in crosssection, the fruit 86 delivered thereto will drop into the trough formedby such V-shape, thus to be gripped thereby. By virtue of thecross-sectional configuration, virtually any size or shape of fruit canbe gripped and transported.

As the fruit 86 are carried by the gripping and transporting mechanismaround the path of rotation of the wheel assembly 10, they nextencounter means, such as the blade assembly 44, for cutting the skin ofthe fruit. As illustrated in FIG. 2, only a small annular portion of thecutting blade 62 projects beyond the cutting-depth-limiting guides 64and 64', so that any cut produced necessarily will be quite shallow,preferably just through the skin of the fruit. As shown in FIG. 1, thecutting assembly 44 is pivotably supported by arm 60 on shaft 52 so thatit may rest gently, under the force of gravity, against the fruit beingpresented thereto. Preferably the blade 62 and cutting-depth-limitingguides 64 and 64' are rotating in an angular direction opposite to thatof the wheel assembly 10. Thus, engagement between the fruit 86 and theblade 62 and cutting-depth-limiting guides 64 and 64' will cause theblade and guide to ride up over the fruit, as shown in FIG. 2, producinga cut 92 through the skin of the fruit while so doing. Since the fruithad been oriented during its passage down the supply trough 18 to haveits axis aligned generally with the longitudinal axis of the troughbefore reception between the members 80 and 80', this cut suitably willbe a plane extending generally through the stem axis of the fruit.

As the fruit continues to be transported around the path defined by itsgripping engagement with members 80 and 80' it begins to approach aportion of such path in which the rollers 42 and 42' deflect theresilient members 80 and 80' toward one another. Such deflection thuseffects a squeezing force upon the fruit skin outer surface in thedirection indicated by the arrows of FIG. 3. This squeezing force, alongwith the centrifugal force resulting from rotation of the wheel assembly10, serves to urge the fruit pulp out of the fruit skin 90, whichremains gripped by the members 80 and 80', through the cut or slit 92 inthe skin produced by the cutting assembly 44. This squeezing forceultimately serves to expel the pulp 88 from the skin through the slit92, in the manner indicated in sectional view of FIG. 4. As the pulp 88is discharged from the skin 90, that skin 90 remains gripped between themutually facing surfaces of members 80 and 80', under the squeezingengagement of those members by the rollers 42 and 42'. By virtue of therotational motion of the wheel assembly 10 imparted to the pulp 88, aswell as the location of this point of discharge of the pulp 88 from theskin 90, the pulp 88 is discharged into the chute 12, where it isdelivered to suitable collecting means. It may be noted that thepositioning of the discharge chute 12, as well as of the pinch rollers42 and 42', may be adjusted by adjusting the position of cross-bar 36upon the arcuate support 32, in a manner generally similar to the methodof adjusting the supply trough 8.

As the gripping and transporting apparatus continues its advance alongits endless path, beyond the point of engagement with rollers 42 and42', the resilient members 80 and 80' again assume their relaxed, openposition, forming a trough-like arrangement having a generally V-shapedcross-section. This return of the members 80 and 80' to theirundeflected position thus releases the grip of those members upon thefruit skin 90, permitting it to drop into the skin discharge chute 92.The removal of the skin from the members 80 and 80' is further effectedby the engagement of rotating brush 30 with the mutually facing portionsof members 80 and 80'. The brush 30 is preferably configured as acircular structure having a tapered peripheral cross-section to closelyengage the interior of the V-shaped trough formed by the members 80 and80'. This brush 30 is rotated in an angular direction the same as thedirection of rotation of the wheel assembly 10, thus maximizing thebrushing action of the engagement therebetween. This brushing thusserves to remove all remaining traces of the fruit skin from thetransporting mechanism.

As the gripping and transporting mechanism continues around its endlesspath, it passes by at least one washing jet 94, which discharges asuitable cleaning fluid, such as water, from the distribution tube 96onto the fruit gripping portions of the members 80 and 80'. This jet ofcleaning fluid thus serves to wash away any traces of the juice from thefruit remaining after the skin has been brushed away by rotating brush30. Thus, the fruit gripping surfaces of the gripping and transportingmeans are cleaned and made ready for reception of additional fruit fromthe supply trough 8 as the wheel 10 continues its rotation.

From the foregoing description, it may be seen that the method andapparatus of this invention provide for continuous separation of pulp offruit from its skin, utilizing a gripping and transporting structurewhich functions on fruit of substantially any commercial size. Theabsence of chemical processing permits the recovery and use of virtuallyall juice which may be extracted during the peeling process and alsoeliminates necessity for washing and possibly damaging the peeled pulp.Also, by virtue of the simplicity of the apparatus and its utilizationof rotary motion, this method and apparatus provides for a smoother,continuous operation with fewer mechanical breakdowns.

While a preferred embodiment of the method and apparatus of thisinvention has been described above with reference to the peeling oftomatoes, obviously numerous other types of fruit having similarrequirements for peeling could be used equally well. Also, while theinvention is illustrated with reference to a circular, wheel-likegripping and transporting mechanism, it is to be understood that theprinciples apply equally well to numberous other configurations,including, but not limited to, the double-wheel and belt arrangement ofFIG. 5. Similarly, other types of guides and devices could be utilizedfor resiliently deflecting the members 80 and 80', in place of therollers 42 and 42'. Accordingly, since these, as well as numerous othermodifications of the disclosed apparatus and method, all within thescope of the invention, will readily occur to those skilled in the art,the scope of this invention is not to be limited by the foregoingdescription but solely by the claims appended hereto.

What is claimed is:
 1. A method of separating pulp from the skin oftomatoes, comprising the steps ofgripping the outer surface of said skinon opposite sides of a plane extending generally through said fruit, bya pair of generally opposed, resiliently deflectable members; carryingsaid fruit around at least a portion of a continuously circular path;then producing a cut through a portion of said skin remote from saidgripping contact and in a plane extending generally through said fruit;and urging said pulp away from said gripped skin through said cut insaid skin by the centrifugal force imparted by said movement around saidcontinuously circular path, whereby the pulp is separated from the skin.2. The method of claim 1 wherein said members are resilientlydeflectable toward one another and wherein said pulp is urged away fromsaid gripped skin by deflecting said members toward one another aftersaid cut is produced to effect a squeezing force upon said skin, wherebythe pulp is urged out of the gripped skin.
 3. The method of claim 2wherein said steps are carried out along a first predetermined portionof said continuously circular path, said first predetermined portionextending between a fruit receiving position and a pulp dischargeposition.
 4. The method of claim 3 wherein said members are deflectedtoward one another at a point in said path adjacent said pulp dischargeposition.
 5. The method of claim 3 further comprising the step ofdischarging said fruit skin from said gripping after said pulp isseparated from said skin, whereby the skin is so discharged at a pointin the endless path following the first predetermined portion thereof.6. The method of claim 5 wherein said discharge is effected bytermination of said gripping by said members and by contacting saidmembers with brushing means.
 7. The method of claim 5 further comprisingthe step of washing the fruit gripping surfaces of said members in aportion of said endless path located between said pulp dischargeposition and said fruit receiving position.